What's a fair value for a UJ datecode 500 4.5L that has many paint chips, a 3-inch crack in the hood, and a missing cover for the focal distance meter? The missing cover and cracked hood are "fixed" with clear packing tape (ugly, but appear to be adequate fixes). Focus speed and accuracy seem good, and the images are sharp.

With prices the way they are going, $3,000. A few years ago I saw a list that put a lens like that around $2,500. I've never seen one in poor condition(looks wise) go for under $2,800.
Canon won't touch the lens otherwise the prices would have skyrocketed on that model.

The drop in filter holder does not have a screw-in filter, rather a piece of glass that is part of the holder, onto which gelatin filters would be held in place with the metal clip-in overlay piece.... unless your lens came with the optional drop in filter holder that accepts 48mm screw-in filters.

thanks for the filter info. I believe my filter holder is the standard one, but I'll double check.

that's a scary story about the $1500 paperweight. I read elsewhere that someone was able to get a new motor for theirs. Does that not suggest the USM is still serviced by some shops? Or is the motor distinct from other non-servicable aspects of USM?

Is there any sense in which "if it aint broke, don't mess with it" applies to these old lenses? That is, might opening her up to clean and lube possibly lead to damage? If not, which are the best places in Chicagoland to have it done? I've heard Calumet mentioned and they're close by.